Problems with A6400 that my GoPro Hero 7 Black don't have

I bought a Sony A6400 about a couple months ago and I'm struggling with dialing in the settings I need. I'm a YouTuber and have been using my GoPro Hero 7 Black as my main camera but would like to bring my A6400 in too... possibly as a replacement. I have a couple problem, though, getting the video and audio to be as good as the GoPro.

I'll be honest here: the Sony has a very convoluted menu and an overload of functions for me. I'm learning here and there, but it's likely I won't need everything in this camera. Here is my shooting situation.

I shoot myself, typically from head to mid-waist, and my background is no more than a couple feet behind me. I stay in a stationary spot and don't walk around. I use key and fill lighting and don't feel I have any exposure issues. On my GoPro, everything is in focus, and I can even put something in front of the camera (to show detail) and it keeps that in focus as well. I bought the Sony because it's touted for having great focus but, for some reason, I get back focus issues and, for putting something up front quickly, there is a delay in target focusing for that. I'd like to have everything in focus, not just me, and all the time. Is there a way to do that?

As for audio, I have a powered mic and I'm not sure if that's an issue with pairing it up with the Sony. I turned the levels down on the camera end but it just doesn't have the warm, clear, and always leveled audio that same mic gets when hooked to the GoPro. Maybe I could switch off some sort of limiter in the Sony?

Even though things are near-perfect with the GoPro, I'd like to have a selfie monitor, not have to deal with barrel distortion during 4K shooting, avoid the overheating issue, and the other quirks of that camera. But, my Sony sits in a box unused because I'm frustrated with the results not measuring up to, of all things, a cheap outdoor vlogging camera. What am I missing here?

I will refine my questions and provide more details, of course, when needed. Thanks for any and all help.